SHM Converge Scientific Abstract ePoster Gallery-Methemoglobinemia in a Covid Inpatient

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A 69-year-old woman with acute lymphocytic leukemia, prior venous thromboembolism on rivaroxaban, and chronic dapsone prophylaxis was hospitalized for symptomatic COVID-19. She initially required low-flow oxygen and was treated with dexamethasone and remdesivir. Early cardiac and inflammatory workup was unrevealing, and chemotherapy was held while dapsone and valacyclovir prophylaxis continued. Blood cultures initially grew gram-positive organisms, prompting broad-spectrum antibiotics.<br /><br />By hospital day 3, her oxygen needs abruptly worsened, requiring high-flow nasal cannula. However, arterial blood gas on a nonrebreather showed a pO2 over 100 mmHg with normal pH and pCO2, but methemoglobin was elevated at 11%. A repeat chest X-ray showed developing pneumonia. Dapsone was stopped, and her oxygenation gradually improved as she was weaned to room air. Serial ABGs showed falling methemoglobin levels, and repeat blood cultures were negative. She was discharged one week later with hematology follow-up.<br /><br />This case highlights that hypoxemia in COVID-19 may be multifactorial and not always explained by lung disease alone. Pulse oximetry can be misleading in the presence of methemoglobinemia, hemoglobinopathies, hypoperfusion, or hypothermia. Dapsone is a recognized cause of methemoglobinemia, which can range from mild, asymptomatic elevations to severe, life-threatening disease.<br /><br />The patient likely had a combination of COVID-19, developing pneumonia, mild anemia, and dapsone-associated methemoglobinemia contributing to her clinical decline. The case emphasizes the need to investigate discordant oxygen measurements or poor response to treatment, especially in complex patients with multiple comorbidities and polypharmacy.

Asset Subtitle

Fatima Chagani

Meta Tag

Author List Asha L. Bansari, Bhagwan Dass, Fatima Chagani, Michael Capozza, Shriharsha Kallahalli

Category Clinical Vignettes

Concept Methemoglobinemia

Concept Hypoxemia

Concept Pulse Oximetry

Concept Blood Gas Analysis

Concept Methemoglobin percentage

Distinguished Non-Finalist

Presenter Organization University of Florida

Presenting Author Fatima Chagani

Track Adult

Keywords

COVID-19

methemoglobinemia

dapsone

hypoxemia

acute lymphocytic leukemia

pulse oximetry

rivaroxaban

remdesivir

dexamethasone

pneumonia

Methemoglobinemia

Hypoxemia

Pulse Oximetry

Blood Gas Analysis

Methemoglobin percentage